Vacuum systems for collecting fluids or fluids containing particulate matter are generally known. One use for such vacuum systems is dental aspirators. Dental aspirators utilize a vacuum apparatus for removing saliva, broken teeth, bone chips, blood or filling materials from the mouth of a patient to allow a dentist to complete the procedure without continual interruptions for the patient to rinse. Dental aspirators are also used in other dental procedures where it is necessary to use a water pick or other device which continuously feeds additional fluid into the patient's mouth, which must be contemporaneously removed. Dental aspirators therefore serve two important functions; permitting a dentist to complete his work without interruption, and providing additional patient comfort during dental procedures.
The known dental aspirator systems generally use flexible evacuation hoses, which are inserted into a patient's mouth during surgery or other procedures. Each dental operatory of an office includes an evacuation hose which is connected to a common piping system. This common piping system is connected to a single, remotely located, vacuum apparatus that services all of the dental operatories.
One known vacuum apparatus has a collection tank, which contains a float to detect the fluid level in the tank. When the fluid reaches a predetermined level, the float blocks a vacuum port such that no additional fluid can be collected in the tank. The vacuum generating source is then turned off and the fluid collected in the tank is drained.
In another known vacuum apparatus, the float moves an actuator which turns off power to the vacuum generating source when the fluid in the tank reaches a predetermined level. When the power to the vacuum generating source is turned off, a valve is opened to drain the collected fluid.
One of the problems inherent in the above described vacuum apparatuses is that once the collection tank has been filled to the predetermined level, the vacuum generating source must be turned off in order for the collection tank to be drained. Whether the vacuum source is manually or automatically shut off and the tank drained, suction is lost in the operatories. The draining process can take five to fifteen minutes, during which time none of the aspirators in the dental operatories are functioning. This time delay interrupts the dentist's work and causes additional patient discomfort.
One solution to this problem is to provide a larger collection tank. However, in a large dental practice with several operatories, it is difficult to determine what collection tank volume is sufficient to provide uninterrupted aspirator service. In practice, a fifteen gallon collection tank has been found to be generally acceptable and generally needs draining only once a day, after the close of business hours. However, depending on the types of dental procedures performed, the collection tank can become filled during business hours, and the vacuum apparatus must be turned off and the tank drained, thereby interrupting the procedures being performed.
The present invention overcomes many of the disadvantages inherent in the above-described dental aspirator vacuum systems by providing an automatically draining vacuum apparatus in which the collection tank is partially drained when the fluid in the collection tank reaches a predetermined level. Vacuum service to the evacuation hoses in the dental operatories is only interrupted for ten to fifteen seconds during the automatic draining of the collection tank, allowing a dentist to continue his procedure without substantial interruption or additional discomfort to the patient.